Heat actuated device



Dec. 19, 1961 PARSONS 3,013,381

HEAT ACTUATED DEVICE Filed Feb. 6, 1958 2 Sheets-Sheet 1 FIG-l g3! FIG.2

IN V EN TOR. GEORGE A. PARSONS BY MW ATTORNEYS Dec. 19, 1961 PARSONS 3,013,381

HEAT ACTUATED DEVICE Filed Feb. 6, 1958 2 Sheets-Sheet 2 25a -i 22a II! 600.

INVEN TOR. GEORGE A- PARSONS ATTORNEYS 1 United States This invention relates to a heat actuated motor of the type in which the motive force is generated by the change of shape of a bi-metal element which is subjected to variations in temperature.

As is well known, it is a characteristic of a so-called bi'metal element to undergo a substantial change of shape when subjected to a variation in temperature. Such bimetals are ordinarily composed of laminations of different metals having different co-efficients of expansion. Thus, for instance, when a thin strip comprising a lamination of two such metals closely bonded together is subjected to heat, one of the metals expand more than the other, causing the strip to bend or curl.

Many attempts have been made to provide power devices by taking advantage of this characteristic of a bimetal element for the purpose of providing suflicient motion to animate displays, advertising devices, toys and the like, but the results have been indifferent for various reasons.

In some of these devices, substantially the entire motion of the object being moved is provided by the change of shape of the bi-metal itself. But devices of this type are too sluggish, uneven and unpredictable in operation for satisfactory results. Furthermore, they do not readily provide vertical motion.

Other such devices have attempted to utilize the change of shape of a bi-metal element to provide motion in a pivoted element but because of the type of heat source used and because of the arrangement of parts, such devices do not operate with sufiicient precision and speed, their frequency or speed of operation cannot be adjusted and they are too unwieldy for practical adaptation to the use of advertising, display devices, toys and the like.

My invention overcomes the above disadvantages and provides satisfactory oscillatory motive power for display devices, scientific instruments, toys and other mechanisms requiring low motive power, in a device which can be both operated and illuminated from a single electric light bulb on house current, which is extremely compact and which is adaptable to many combinations of animation and illumination.

An object of the invention is to provide a simple, compact, inexpensive power operating device.

Another object is to provide in such a device adjustable means to vary its speed or frequency of operation and for bringing it to an optimum condition of operation.

Other objects will be apparent from the description together with the accompanying drawings in which:

FIG. 1 is a top plan view of an embodiment of the invention.

FIG. 2 is a sectional view in front elevation taken along the lines 22 of FIG. 1.

FIG. 3 is a front elevational view of a modified form of the device.

FIG. 4 is a top plan view of the apparatus shown in FIG. 3.

Referring to FIGS. 1 and 2, this embodiment of my invention includes a box or casing 1 conveniently made of cardboard or other inexpensive material and having a front wall 2, a back wall 3 and side walls 4 and 5 and open at the top and bottom. The bottom edges of the front and side walls may be partly cut away to allow air to pass freely into and upwardly through the box for a purpose to be described. The back wall 3 may be additionally ventilated by louvres 12 formed by punched out portions 13.

atent O Patented Dec. 19, 1961 A platform 15 having ears 16 is attached to the inside of the box 1 by fitting the ears 16 through openings 18 in the side walls 4 and 5. The platform 15 may be conveniently made of sheet metal for additional strength.-

Mounted on the platform 15 is a stand 20 having a pair of uprights 21 having recesses 22 at their upper edges which journal a pin 26 forming a pivotal support for a balanced beam 25 which has a pair of arms 27 and 28.

Means are provided for mounting an electric light bulb 32 including a socket 30 mounted on the platform 15 adjacent the arm 27 to provide a heat and light source.

A bi-metal element 35 is carried by the arm 27 adjacent the position of the bulb 32 in the socket 30. and a weight 36 is carried by the bi-metal element.

A shield 40 at least partly closely surrounds the lower portion of the bulb 32 and provides a relatively cool zone adjacent the bulb 32.

A reflector 41 is mounted conveniently on the rear wall 3 of the box 1 and closely spaced in back of the upper portion of the bulb 32 above the shield 40* and provides a relatively hot zone above the cool zone adjacent the bulb by increasing the concentration of heat around the unshielded upper portion of the bulb.

The bi-metal element 35 is arranged to be moved up and down substantially vertically relative to the bulb, outside the shield 40 and inside the reflector 41 between the relatively cool zone and the relatively hot zone above it during oscillation of the balanced beam 25.

When the bi-metal element 35 moves downwardly into the cool zone, it changes shape moving the weight 35 and shifting the center of gravity of the beam 25 slightly toward the pivotal support pin 26, thereby inducing clockwise movement of the beam 25, raising the bi-metal element 35 into the hot zone. The heat from the upper part of the bulb 32 causes a change of shape of the bi-metal element 35 in the opposite direction, moving the weight 36 away from the pivotal support pin 26, thereby inducing counterclockwise movement of the beam 25, and the bi-metal element 35 returns to the cool zone, sustaining the natural periodic oscillation of the beam 25.

The arrangement of the bulb 32, the shield 40 and the reflector 41 provides a chimney effect which draws relativel cool air from under the platform 1.5, causing it to move upwardly from the bottom to the top of the box 1, thereby reducing the ambient temperature around the shield 40 and providing a greater temperature differential between the cool Zone and the hot zone at the upper part of the bulb, with a sharp demarcation between the temperature zones by reason of the fact that the chimney effect carries the hot air around the upper part of the bulb V upwardly and away from the cooler zone below.

The movement of the weight 36 toward and away from the pivotal support pin 26 is of small magnitude, just sufiicient to initiate and sustain the oscillatory movement of the balanced beam 25 in a natural periodic oscillation. It is therefore sufficiently responsive to synchronize with an oscillation of adequately rapid frequency and it also responds to adjustments in frequency of oscillation over a desirable range.

The other arm 28 of the beam 25 removably supports a transparent element 45 conveniently referred to as a light object 45 which is moved up and down when the beam rocks.

A counterweight 60 on the opposite side of the beam 25 counterbalances the weight 36 and the object 45.

Means including an eccentrically mounted weight 61 are provided adjustably to raise and lower the center of mass of the beam 25 relative to the pivotal support pin 26 to vary the frequency of the oscillation of the beam 25. This is accomplished by rotatably adjusting the position of the weight 61 with respect to its mounting bolt 62.

Means which may include another eccentrically mounted weight 64 are provided to adjust the center of gravity of the beam horizontally relative to its pivotal support pin 26 to achieve fine balance by rotatably positioning the weight 64 with respect to its mounting bolt 65.

To operate the machine, the light cord 31 is plugged into a power supply to energize the light bulb 32. The heat from the bulb 32 initiates oscillatory motion of the beam 25.

A modification of the form of the operating device is shown in FIGS. 3 and 4 in which the bulb mounting means 36a for a bulb 32a is mounted on the left-hand end of the balanced beam 25a and counterbalanced with a weight 60a. The weight 60a may be raised and lowered to adjust the period of oscillation of the beam 25a.

The pivotal support for the beam 25a may include separate pin elements 26:: supported in an insulated block 29 and journalled in recessed metallic elements 22a carried on insulated uprights 21a. The metal pins 26a and their supports 220 thus provide relatively movable conductors for the lead wires 31a and 31b forming the electric current supply for the bulb socket a and bulb 32a.

As seen in FIG. 3, the shield 46a for the bulb 32a is fixed by a mounting 4 2 to the base or platform 15a on which are also mounted the uprights 21a for the pivotal support. The reflector 41a is also fixedly mounted.

The bi-metal element 35a is mounted on an arm 27a on the left side of the beam 250 and has a weight 36.4 on its outer end. It is arranged to move with the bulb 32a up and down with the oscillation of the beam 25a, between and relative to the shield a and the reflector 41a.

When the left-hand end of the beam 25a moves down, the shield 40a becomes interposed between the bulb 32a and the bi-metal element 35:: causing the latter to move the Weight 36a to the right shifting the center of gravity of the beam 25a to the right. When the left-hand end of the beam 25a moves upwardly above the top of the shield 40a, heat from the bulb 32a concentrated by the reflector 41a causes the bi-metal element 35:! to change shape in the opposite direction. moving the weight 36a and the center of gravity of the beam 250 to the left, reversing the oscillation of the beam 25a.

An object 45a may be fixedly mounted in front of the light bulb 32a.

When a bulb is used as the heat and light source, it is preferable to use a shield as previously described to pro vide a cool zone, that is to reduce the ambient temperature.

The apparatus may be enclosed in various forms of boxes or casings to suit the particular requirements.

As will be apparent from the description of the invention, other arrangements are within its scope and will readily suggest themselves according to requirements,

I claim:

1. A heat actuated device comprising a balanced beam having a pivotal support and capable of a natural periodic oscillation about said support, a heat source at one end of said beam, a bi-metal element carried on said one end of said beam near said heat source and a weight carried by said bi-metal element, said bi-metal element being arranged to be moved up and down by said end of said beam alternately closer to and further away from said heat source during oscillation of said beam and in response to the resultant alternate heating and cooling of said element to move said weight toward and away from said pivotal support shifting the center of gravity of said beam sufiiciently to sustain said natural periodic oscillation of said beam, and an object connected to said beam to be oscillated thereby.

2. In the combination as set forth in claim 1, means adjustably to raise and lower the center of mass of said beam relative to said pivotal support, thereby to vary the frequency of said natural periodic oscillation.

3. In the combination as set forth in claim 1, means to adjust the center of gravity of said beam horizontally relative to said pivotal support.

4. A heat actuated device comprising a balanced beam having a pivotal support and capable of a natural periodic oscillation about said support, means for mounting an electric light bulb providing a heat and light source at one end of said beam, means including a shield surrounding at least part of said bulb providing zones of different temperatures one above the other adjacent to said bulb, the higher temperature zone being above the lower temperature zone, a bi-metal element carried on said one end of said beam near said bulb and a weight carried by said bi-metal element, said bi-metal element being arranged to be moved upand down by said end of said beam alternately through said zones of different temperatures during oscillation of said beam and in response to resultant alternate heating and cooling of said element to move said weight toward and away from said pivotal support shifting the center of gravity of said beam sutficiently to sustain said natural periodic oscillation of said beam.

5. In the combination as set forth in claim 4, means adjustably to raise and lower the center of mass of said beam relative to said pivotal support, thereby to vary the frequency of said natural periodic oscillation.

6. In the combination as set forth in claim 4, a reflector for said bulb above said shield, said bi-metal element and said bulb being movable up and down between said shield and said reflector.

7. A heat actuated device comprising a balanced beam having a pivotal support and capable of a natural periodic oscillation about said support, means for mounting a fixed electric light bulb providing a heat and light source adjacent one end of said beam, a fixed shield at least partially surrounding a lower portion of said bulb and providing a relatively cool zone adjacent said bulb, a fixed reflector spaced from an upper portion of said bulb and providing a relatively hot zone adjacent said bulb, a bi-metal element carried by said one end of said beam and a weight carried by said bi-metal element, said bi-metal element being arranged to be moved up and down by said end of said beam outside said shield and inside said reflector between said cool and hot zones during oscillation of said beam and in response to the resultant alternate heating and cooling of said element to move said weight toward and away from said pivotal support shifting the center of gravity of said beam sufficiently to sustain said natural periodic oscillation of said beam, and an element connected to said beam to be oscillated thereby.

8. In the combination as set forth in claim 7, means adjustably to raise and lower the center of mass of said beam relative to said pivotal support, thereby to vary the frequency of said natural periodic oscillation.

9. In the combination as set forth in claim 7, means to adjust the center of gravity of said beam horizontally relative to said pivotal support.

10. A heat actuated device comprising a balanced beam having a pivotal support and capable of a natural periodic oscillation about said support, means for mounting an electric light bulb on one end of said beam to provide a heat and light source, a fixed shield adjacent said bulb and a fixed reflector above said shield and spaced from said bulb, a bi-metal element carried by said one end of said beam substantially at the level of said bulb in said mounting means and a weight carried by said bi-metal element, said bi-metal element being arranged to be moved up and down by said end of said beam outside said shield and inside said reflector while said bulb moves upwardly above said shield inside said reflector and downwardly inside said shield during oscillation of said beam, said bulb, shield and reflector operating alternately to cool and heat said bi-metal element thereby to move said weight toward and away from said pivotal support, shifting the center of gravity of said beam sufficiently to sustain said natural periodic oscillation of said beam,

11. In the combination as set forth in claim 10, means associated with said pivotal support to provide electric current to said bulb mounting means.

12. A heat-actuated motor comprising a pivot, 21 balanced beam rockable on said pivot, means near an end of said beam for maintaining a relatively hot zone immediately above a relatively cool zone, a bi-metallic element mounted on said beam near said end thereof and movable up and down between said hot and cool zones to be relatively heated and cooled thereby as the beam rocks, a weight carried by said bi-metallic element and movable thereby toward and from said pivot as said element reacts to temperature changes in moving from zone to zone, and an element connected to said beam to be oscillated thereby.

13. Apparatus including a balanced beam, a pivot therefor, a source of heat and light, a bimetal element on one end of said beam movable upward and downward nearer to and farther from said source of heat and light to be relatively heated and cooled thereby, and capable of bending more or less according to its temperature, a weight on said bimetal element movable toward and away from the pivot of the beam by changes in the bend of said bimetal element to maintain the oscillation of the beam, and an element connected to said beam for oscillation thereby.

14. Apparatus including an enclosure and within said enclosure a source of heat and light, a balanced beam, a bimetal element on said beam capable of movement to positions nearer to and farther from said source and thereby to bend the bimetal element more or less as it is relatively heated and cooled by moving nearer to or farther from said source, a weight on said bimetal element movable toward and away from the pivot of the beam by changes in the bend of said bimetal element to maintain the oscillation of the beam, said enclosure having openings for the entrance and exit of air below and above respectively said source of heat and light and thereby providing a chimney-like movement of air upwardly past said source and bimetal element, and an element connected to said beam for oscillation thereby.

References Cited in the file of this patent UNITED STATES PATENTS 902,496 Lafond Oct. 27, 1908 2,337,084 Crise Dec. 21, 1943 2,687,005 Ingersoll Aug. 24, 1954 2,687,006 Lyons Aug. 24, 1954 2,687,007 Reitz Aug. 24, 1954 2,690,050 Nichols Sept. 28, 1954 2,817,916 Yarrow Dec. 31, 1957 FOREIGN PATENTS 14,764 Australia Aug. 29, 1934 1,082,860 France June 23,- 1954 204,100 Great Britain Sept. 17, 1923 454,626 Great Britain Oct. 2, 1936 

